This invention relates to a water-cooled internal combustion engine using hydraulic oil lubrication and a cooling water pump driven as a function of the load of the internal combustion pump.
In this type of water-cooled internal combustion engine the rotational speed of the cooling-water pump is dependent upon the engine speed through a mechanical drive using V-belts, toothed gears or toothed belts. Since the water pump for the cooling water is designed for maximum load of the internal combustion engine, for partial loads, the pump delivers quantities of cooling water which are not needed for cooling the internal combustion engine.
The quantity delivered by the oil pump of an internal combustion engine must be such that when the rotational speed during operation of the internal combustion engine is at its lowest, sufficient oil will be delivered for lubrication. As is known, at higher rotational speeds the excess oil is, therefore part of the energy which must be produced in the oil pump is wasted.